Thread: Amp Head and 2x10 Cab

I haven't cleaned up any of the resurrected hardwood yet so got stuck into the centre panel construction.

First up was cutting and thicknessing my plank of Purple Heart into 6mm strips. I was actually quite disappointed when I first cut into it as it seemed like I'd been ripped off. It looked just like a piece of Bunnings Meranti that had been stained purple on the outside. I noticed about half an hour later however that the freshly cut piece was changing colour and a couple of hours in the sun had it once again back to the bright purple that I'd paid for...

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The Silky Oak was cut to size and two Purple Heart strips were glued to each of the Silky planks. These were then planed down to size and are ready for attaching the hardwood outer panels.

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Whilst the glue was drying on the planks I got the speaker baffle underway.

A very quick circle cutting jig was made up from a piece of scrap plywood and the little router put to good use on the speaker holes.

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The baffle is pretty much complete now, just needs to have the top and bottom edges beveled so it will sit inside the cabinet at a 15 degree angle and the speaker bolt holes sorted out.

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Watching.

You got a link to the details of the P1 Extreme?

The P1 Extreme is part of the AX84 group of amp projects and can be found at www.ax84.com

It was quite a bit of work, my first attempt at building an amp, but it turned out quite well. I'm pretty happy with the finish too, it came up looking great. Not so easy to photograph though...

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It's a good unit but the kit was quite expensive to ship to Australia. I've been collecting parts for an Australian Lamington II amp and hope to have that underway soon as well.

I hadn't been to the AX84 site for ages.

Where did you get your kit from?

I started building something similar to the Lamington II back in 2001.

It is based on the AB763 circuit but mine is dual channel without the trem. (Circuit calls it a Vibrato but that is not technically correct.)

I started building it on a 1U 19" rackmount enclosure from Jaycar but about half way through it I realised that the material is not strong enough to make a good chassis out of.

I have since had some Ali custom folded for chassis material but I haven't gotten around to moving the component off the the flimsy base onto the new one.

What parts are you looking for?

Would you like a slice of my folded Ali for you chassis or do you want it to be a lamington tray?

Also part way through a build of a small amp based on the Matchless Spitfire with a 2nd channel using an EF86 like the one used by the 18 watt guys.

It will be a bit like a Matchless Nighthawk.

The kit came from Doberman Music Products whom I believe are the same people that run the AX84 site. It cost me around $90US to have the kit delivered but it was definitely worth it for my first attempt. I'm still waiting on an upgraded output transformer and will refit that one when it arrives.

Looks like you've made plenty of amps so far, I'm only just getting started so I'm a little short on knowledge at this stage...

I liked the Lamington II since it used local components and I've managed to source both power and output transformers for a total of $54. Not sure it's going to sound real great but it's worth having a go at.

I'd love a slice of aluminium for the chassis, never really planned on using the Lamington tray... Tell me the price and postage to Sydney and we'll work something out.

Just followed your 18Watt link, boy there's still a lot of stuff for me to explore...

Hey Stevemc32,

Nice job on your electronics there mate!, Ive built my own Hifi power amps and am currently working on an all valve preamp, I love it! what your doing is exactly what I will be doing as soon as I can afford it (wish that was now!), keep us posted, and keep on with the awesome work, Well Done

Pete

I have enough put away to last me more than a lifetime so I don't want anything other than postage.

I'll dig it out tomorrow & take a picture of it & get you some dimensions.

It will probley cost about $10 or $12 to post.

Thanks Cliff, that's mighty generous. I look forward to seeing it tomorrow with my postage money ready to go.

Thanks for the comments Pete. Hopefully the cabinets turn out as well as the amp did. Still not sure on the combination of colours but we'll see how it will look once the old hardwood is cleaned up.

Lookin good so far steve. I really like the purple heart mate.

The piece on top is 2mm thick & a bit over 155mm wide & 50mm high.
It gives you about 150mm of usable flat surface on the top.

The 2 pieces on the bottom are 1.6mm thick otherwise the bottom piece is the same dimensions as the top piece.
The bit lying inside is folded up slightly smaller with only about a 22mm leg on it to fit neatly in the ends of the bigger stuff to make end caps.

I have 4' (1200mm) of each.

If you draw up a rough rectangle about 6" (150mm) by about 12" (300mm) & sit your transformers on it & then draw where you will put your valve bases I think it should all fit.

Let me know if 12" (300mm) is not enough, I could make it 16" (400mm)

12 x 6 sounds great cliff. On the mobile at the moment so will pm tonight when home regarding postage. Thanks.

Originally Posted by floody_85

Lookin good so far steve. I really like the purple heart mate.

Thanks floody, it's definitely an interesting timber!

Where did you get your transformers?

Have you had a look at WES Components?
Valves

I have an account with them, they have some good bits & pieces.
Have a look at the last 5 pages of this catalogue.
http://www.wagner.net.au/catalogue/0...conductors.pdf
The prices have been removed 'cos it is straight out of the Trade Price List.

I'll chop up a bit of chassis for you tomorrow.

Did the kit you got come ready drilled or did you have to punch the holes yourself?

What gear do you have for doing the chassis work?

McJing have step drills & taper drills that are just the shot for holes for valve bases.

A nibbling tool is also useful for chassis work, particularly if you want to lie your transformers down on the chassis with one side of the winding poking through the chassis.